And joseph schmitt



(M d l.)

o'e G. SGHRADER a J. SCHMITT.

PROCESS-0F FORMING SCREW APS..

No. 406,479. Patented Jly 9, 17889` UNITED STATES PATENT OFFICE.

GEORGE SCHRADER, 'OF NEW YORK, AND JOSEPH SCHMITT, OF BROOKLYN,

" NEW YORK.

PROCESS OF FORIVllNG SCREW-CAPS.

SPECIFICATION forming part of Letters i Application filed July 5, 1887.

Patent No. 406,479, dated July 9, 1889.

Serial No. 243,328. (Model.)

To all whom t may concern:

Beit known that We, GEORGE SCHRADER, of New York city, New York, and JOSEPH SCHMITT, of Brooklyn, Kings county, New York, have jointly invented certain new and useful Improvements in the Process of Forming Screw-Caps for Bottles, Jars, and other Purposes, of which the following is a specification.

Our invention has been more especially designed for the manufacture of screw-caps to cover the screw-necks of rubber water-bottles; but it is equally applicable for screw-caps for many other purposes.

Heretofore such screw caps have ordinarily been formed by casting, the cap and its projecting T-handle being cast in one piece, and the screw-thread being then cut in the casting by tapping, while the annular recess above the thread to receive the packing-disk is. formed by a turning-tool. In a later method the cap has been stamped out of thin sheet metal with a slot in the top, into which a flat handle of sheet metal has been soldered, while the screw-thread is cut in a separately-formed screw-ring which is `soldered within the thin stamped cap, thus leaving al recess for the packing-diskabove the ring in which said disk is socketed. A

Now the aim of our invention is to manufacture such screw-caps much more rapidly and cheaply, to reduce the operations and number of parts therein, and render the cap stronger and more perfect for its purposes. To these ends we stamp up the cap from thick sheet metal and eut a screw-thread directly therein, and we so swage or compress the cap as to have the threaded part of contracted size, with an annular enlargement or recess above the thread to form the socket for the packing-washer. We also form the handle of a loop of wire whose ends are inserted in two holes cut through the top of the cap and there riveted or otherwise secured.

Our invention therefore consists, mainly, in the features above outlined, whereby a very cheap, strong, and perfect cap is produced, as hereinafter fully set forth.

In the drawings annexed, Figure l represents a section of a cap in its first stage or when first stamped from sheet metal. Fig. 2

yrecess which comes down upon and shapes is a section at the second stage when it is tapped or screw-threaded. Fig. 3 gives a section of the cap and the dies at the third stage, in which the tapped cap is swaged or contracted to form the enlargement or recess above the screw-thread. Fig. 4 shows the wire loop-handle and the cap perforated to receive the ends thereof. Fig. 5 shows the fifth stage, where the Wire loop is riveted in the cap. Fig. 6 is an inverted plan of Fig. 5. Fig. 7 shows a perspective view of the finished cap. Fig. 8 gives a section of the finished cap screwed upon the neck of the water-bot tle with the packing-washer in the socket of the cap. Fig. 9 gives a section of a modification.

Referring now to the drawings, the process of manufacture will be easily understood. TheA caps a are first stamped up by suitable dies out of thick sheet metal in the form shown' in Fig. 1-that is, preferably in the form of plain cylindrical cup-shaped blanks with a rounded top-the method of and means for such stamping being well understood, and therefore needs no description. In this cupshaped blank is next cut a screw-thread b, by tapping or otherwise, as 'seen in Fig. 2, the edge of the cap being at the same time turned off true; but the thread does not extend into the cap the full depth, a blank or unthreaded space being left near the top of the cap, as shown in Fig. 2. The threaded cap is next swaged in the dies shown in Fig. 3, so as to contract the threaded part, leaving the blank or unthreaded part in the top wider than the threaded neck, and thus forming an annular recess orsocket c to securely receive the packing-washer d when inserted therein, as in Fig. 8.

The construction of the dies for the swaging operation will be readily understood from Fig. --that is, the lower `die f has a flaring opening or socket corresponding tothe shape y to be imparted to the cap, and from it rises a 95 strong spring-bolt or yielding anvil-pin g, which rises in the center of the cap and abuts against the top of the cap interiorly, as shown, while the upper die n has a slightly-concave the top of the cap. Vhen the dies are separated, the spring-pin g rises above the lower die f by the action of its spring e, limited by Abetween them, as seen in Fig. 3, the pin g yielding to the descent of the upper die n, as will be understood from Fig. 3. The threads in the plain cap in Fig. 2 are made sufficiently large to allow for the subsequent contraction in the third stage, (shown in Fig. 3,) so

that after the threaded part has been contracted, as described, it Will be a Ycorrect t for the screw-neck for which it is adapted, as will be readily understood from Fig. S. In thus swaging the unfinished cap or cupshaped blank, the lower or neck portion is contracted, while the upper or dome-shaped portion is crushed downward and outward by the same operation sufficiently to just ill the dies and take the desired form, as shown, without the use of a filling to transmit the pressure to the interior walls .of the blank.

After the contracted cap h as been removed from the dies in Fig. 3, it is neX-t perforated with two holes 7c on the top, equdistant .on each side of the axial center, as seen in Fig. 4, and a handle-loop l is then formed of wire, preferably of a round section, as shown in Fig. 4, and the ends of this loop are inserted trated in said gures, which is a Very simple and effective operation, and secures the loop most ir-mly tothe cap. When the handle is thus secured to the cap, the cap appears eX- 'teriorly as in Fig. 7, and is inished'or complete, it being only now necessary to embed ,or socket a packing-disk or washer d up in the annular recess or socket c inthe top of the cap, and the cap may now be screwed down tightly on the screw-neck m of the waterbottle, as shown in Fig. 8, andwill form an air and water tight cover thereon, as will be.

readily comprehended.

It will be noted, on reference to Fig. S, that the top of the cap is slightly domed at the center above the center of the Washer, so that the riveted ends of the handle do not touch the washer, which thus bears marginally against the flat marginal portion of the cap, and thus insures an even regular bearing for the Washer between the top of the cap and the edge of the screw-neck m, which insures a tight joint and prevents injury to the washer, as will be readily appreciated.

It may now be seen that this mode of manufacture presents many advantages, for it will be seen that it dispenses with the waste and cost due to casting, and it yet produces the lcaps in one piece .of sheet metal with screwthread and recess for washer without any waste of metal and byafew direct operations, which renders the manufacture much cheaper and the cap superior to what has heretofore obtained.

The process of forming screw-.caps herein described, which consists, iirst, in stamping a cylindrical cup-shape blank out of sheet metal; second, cutting a screw-thread therein, an.d, third, swaging between suitably-formed dies, so as to con-tract the lower or neck portion, while the upperor dome-shaped portion is crushed downward and expanded ,outward by the same operation sufficiently to just fill the dies and take the desired form, as shown, without the vuse of a filling to transmit the pressure to the interior walls of the blank, substantiallyas shown and described.

GEO. SCHRADER. JOSEPH SCHMITT.

lVitnesses:

JNO. E. GAVIN, JOHN BECKER. 

